I am writing a NetBeans module that extends the image viewer to support additional file types (specifically, TIFF and 
other multi-page formats).

I have a TopComponent that inherits from the ImageViewer class and inserts additional UI components into the JToolBar. 
The component's ChangeListener needs to call ImageViewer.updateView(ImageDataObject obj) however this method has default 
(package) access.

My module resides in a different classloader, so even if I repackage MyTopComponent into org.netbeans.modules.image, I 
receive the following exception:

java.lang.IllegalAccessError: tried to access method 
org.netbeans.modules.image.ImageViewer.updateView(Lorg/netbeans/modules/image/ImageDataObject;)V from class 
org.netbeans.modules.image.MyTopComponent

Obviously, I can work around this problem using reflection. However, I think it would be a worthwhile improvement to the 
extensibility of the NetBeans platform if the Image plugin were redesigned to cater for developers who wish to override 
and extend its functionality.